Recurrent laryngeal nerve (RLN) palsy during thyroidectomy is associated with multiple risk factors as patient- and surgeon-related bailiff. The risk is greater for thyroid cancer, Graves' disease, re-operation, and mediastinal goiter in less experienced centers and in patients in whom the RLN could not be identified during operation. Anatomical landmarks exist to identify RLN. Nevertheless, transient and permanent RLN injuries still exist. Intraoperative neuromonitoring (IONM) has been introduced to facilitate identification and verify functional integrity of the RLN in thyroid surgery. In this chapter, we present relevant medical literature and personal experience on thyroid surgery with IONM. Technical, medical, and legal aspects of monitoring are discussed.